Ok, the engine is freshly rebuilt as well as the carb. What started happening yesterday was that the engine took a little while of cranking over before it would fire up. After it was running and up to normal operating temp. If you floored the gas pedal, it would backfire through the carb. If you step on the gas half way, the engine dies and then picks up if you let off the gas.

The dwell on the points was just set to factory spec and the timing was done the same as well. Prior to yesterday, the engine ran strong and had no problems at all. Could the engine be breaking in and the timing needs to be adjusted more? Could the carb need to be richened or leaned out?

man that sounds like it could be a number of things. does the engine smooth out at around 1500 rpm? have you pulled a spark plug(s) to see the electrodes? How old is your coil? what type of spark is it giving? It could be a combination of things such as vacuum leak, carburetor flooding (i.e. stuck floats), bad ignition wires, cracked distributor cap, corroded points, bad ballast resistor, etc etc.